Police seized 93kg of drugs and chemical additives - enough to produce HK$10 million worth of ketamine - in a raid on a subdivided flat in Sham Shui Po.

Officers later arrested two suspected members of the Wo Shing Wo triad, and one woman, at their Kwai Chung homes in Wednesday's operation. Police were still looking for at least three other suspects in the case last night.

No one was inside the subdivided flat in Cheung Sha Wan Road when officers entered at about 10am on Wednesday. Some 27kg of high-grade ketamine, 66kg of chemical additives and drug manufacturing equipment was seized.

The additives, including caffeine, were used to dilute the high-grade ketamine before its distribution, a police investigator said. 'The seizure could produce more than 93kg of ketamine,' he said. 'Because the drug is sold for about HK$110 a gram, the consignment has a street value of about HK$10 million.'

The drugs were due to be distributed through cybercafes and games centres in Tsuen Wan, Kwai Chung and Tai Po.

The drugs were stored in five plastic containers and hidden in a closet in the flat. Air freshener sprays were found at the scene, and were probably used to disguise the chemical smell emitted during drug-making, the officer said.

Controlled by the Wo Shing Wo triad, it was set up about two months ago, he said. 'An investigation learned that the centre was moved around every two or three months, to avoid police detection,' he said. The officer suspects the drugs were smuggled from the mainland.

No one has been charged yet.

Detectives from the Kwai Tsing district's anti-triad squad are investigating whether the drug-making centre was linked to a syndicate that recruited young people to sell illegal drugs after getting them hooked on free drugs.